JPH0413193A - Musical sound generating device - Google Patents

Abstract

PURPOSE:To make natural connections of musical sounds and to prevent an unnecessary harmonics of high order from being generated by composing waveform data to be stored in a waveform memory of waveform data on the rising part of a musical sound, waveform data obtained by adding data weighted with an attenuation characteristic and data weighted with a rising characteristic, and composite waveform data of a single period. CONSTITUTION:The waveform memory 9 is stored with the musical sound waveform data, i.e. waveform data on a source musical sound at the rising part of the musical sound, data obtained by cross fade mixing, wherein the data obtained by weighting a specific section of the stationary part of the source musical sound with the attenuation characteristic, i.e. fade-out processing and data obtained by weighting waveform data of the single period composed of the wavelength in an optional section of the stationary part of the source musical sound with the rising characteristic continuously for the specific section B, i.e. fade-in processing, in the specific section B following the rising part A of the musical sound, and the composite waveform data of the single period at a part E read out repeatedly following the section B. Consequently, the unnaturalness of the musical sound which is generated is eliminated and no unnecessary harmonics of high order is generated.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a musical tone generating device used for example in an electronic keyboard, an electronic piano, a synthesizer, etc. The present invention relates to a musical tone generating device that generates musical tones by repeatedly reading out musical tones.

(Prior Art) Conventionally, musical tone generating devices have been known that generate musical tones by sequentially reading musical waveform data stored in a waveform memory and generating sounds.

Some musical tone generators obtain a continuous musical tone by storing in advance the entire waveform of a musical tone from the beginning to the end in a waveform memory, and sequentially reading out the waveform from the beginning. However, musical tone generators employing this method require a huge amount of memory capacity and have the drawback of being expensive. Therefore, a multi-cycle waveform of a predetermined section starting from the rising edge of a musical tone is stored in a waveform memory, reading is started from the beginning of the predetermined section, and when read at the end, a specific section at the end of the predetermined section is repeatedly read. There are things you can do to obtain a sustained musical tone.

However, when this method is adopted, it is difficult to read out the waveform data of the specific section of the terminal end part continuously at a precise predetermined period.
As shown in (showing the case where the data is read out repeatedly in a periodic manner), discontinuous portions N occur in the repetitive portions. When such a discontinuous part N occurs, the connection becomes unnatural, and even if the wave is a sine wave, many unnecessary high-order overtones will occur, as shown in the frequency characteristic diagram in Figure 9, and the high quality sound will deteriorate. The drawback was that it was not possible to obtain musical tones.

(Problems to be Solved by the Invention) As described above, the present invention stores a plurality of periodic waveforms in a predetermined section from the uphill part of a musical tone in a waveform memory, starts reading from the beginning of the predetermined section, A method that obtains a sustained musical tone by repeatedly reading out a specific section at the end of the predetermined section after it has been read to the end,
When repeatedly reading out waveform data of a predetermined period in a specified end section, it is difficult to read out the waveform data accurately and continuously at a predetermined period, and discontinuous portions occur in the repeated portions, making the connection unnatural and unnecessary. This was done to solve the problem of not being able to obtain high-quality musical tones due to the occurrence of many high-order harmonics.It also prevents discontinuous parts from occurring when repeatedly reading out a waveform of a predetermined period in a specific section at the end. To provide a musical tone generating device which can obtain high-quality musical tones by preventing generation of musical tones, thereby making the connection between musical tones natural, and preventing the generation of unnecessary high-order overtones.

[Analysis of the Invention] (Means for Solving the Problems) The musical tone generating device of the present invention generates waveform data of a rising portion of a musical tone and waveform data of a steady portion of a musical tone following the rising portion of the musical tone. It is equipped with a waveform memory that has been stored in advance, and the waveform data of the rising part of the musical tone is stored in one
The musical tone generating device generates a musical tone by repeatedly reading out the waveform data of a steady portion of the musical tone after reading it twice, and the waveform data stored in the waveform memory includes the waveform data of the rising portion of the musical tone and the waveform data of the following musical tone. The waveform data included in a predetermined section of the steady portion of the tone is weighted with attenuation characteristics, and the single-period synthesized waveform data synthesized based on the waveform data of an arbitrary section of the steady portion of the musical tone is added to the predetermined section. The waveform data is characterized in that it consists of waveform data in which the same number of included waves are connected and weighted according to the rise characteristic, and the following single-period composite waveform data follows.

(Function) In the present invention, when storing musical waveform data in the waveform memory, the waveform data of the original musical tone is stored as is for the rising portion of the musical tone, and the predetermined interval following the rising portion of the musical tone is a steady portion of the original musical tone. weighting of attenuation characteristics, that is, fade-out processing, to a predetermined section of , and weighting of rise characteristics by connecting single-period waveform data synthesized from waveforms of arbitrary sections of the steady portion of the original musical tone for the predetermined section; In other words, a cross-fade mix is performed by adding the fade-in processed data, and the subsequent delayed readout portion stores the single-period synthesized waveform data. When generating a musical tone, the rising portion and predetermined section of the musical tone are read out only once, and finally, single-period waveform data is repeatedly read out to generate a continuous musical tone. As a result, the transition from the rising part of the musical tone to the repeatedly readout part is performed smoothly, and since the waveform data that is repeatedly read out is composite waveform data, discontinuous parts do not occur, and therefore, the musical tones that are sounded are unnatural. This also eliminates unnecessary high-order overtones, making it possible to obtain high-quality musical tones.

(Embodiment) FIG. 1 is a block diagram showing the configuration of an electronic musical instrument to which a musical tone generator according to the present invention is applied.

In the figure, a central processing unit (hereinafter referred to as rCPU).

1 is a read-only memory (hereinafter referred to as FROM).

Each section of the electronic musical instrument is controlled by sequentially reading and executing programs stored in the program memory section 2 via the system bus 14.

The ROM 2 includes a program for operating the CPUI, timbre data, and other various fixed data.

The readable/writable memory (hereinafter referred to as rRAMJ) 3 is
It transfers and stores predetermined data stored in the ROM 2, and also has various registers for controlling the electronic musical instrument and a working area for work.

The keyboard 4 is a group of keyboard switches that transmit the player's key press and release actions. Switch information from the keyboard 4 is sent to the touch sensor 5.

The touch sensor 5 uses a well-known touch detection circuit to detect a key code indicating pressed/released keys and touch data indicating the strength of the key press, and sends the detected keys to the input/output interface 6.

The panel 7 is a group of switches including a power switch, a mode designation switch, a tone selection switch, a rhythm selection switch, various effect switches, and the like. The settings of the switches on the panel 7 are detected by a panel scan circuit (not shown) and sent to the input/output interface 6 as a panel switch code.

The input/output interface 6 sends key codes and touch data of pressed and released keys, and panel switch codes from the panel 7 to the cput via the system bus 14.

The tone generator 8 controls the generation of musical tone signals. In other words, control is performed to generate a sustained musical tone by sequentially reading waveform data corresponding to the tone specified on the panel 7 and the key code of the pressed or released key on the keyboard 4 from the waveform memory 9. . Details of this tone generator 8 will be described later.

The waveform memory 9 stores a plurality of waveform data corresponding to tone colors or heights, and the tone generator 8
One piece of waveform data is selected according to address data from and read out sequentially. The waveform data read from the waveform memory 9 is sent to the multiplier 1 as a musical waveform signal.
1. Details of the musical waveform data stored in the waveform memory 9 will be described later.

The envelope generator 1o is connected to the system bus 14.
It generates an envelope signal that controls the amplitude of the musical waveform signal in accordance with envelope data sent from the music waveform signal. The envelope signal generated by the envelope generator 10 is also supplied to the multiplier 11.

The multiplier 11 multiplies the musical waveform signal from the waveform memory 9 and the envelope signal from the envelope generator 10 to generate a musical tone signal to which an envelope is added. This allows the intensity of the sound to be controlled and emitted. The digital musical tone signal to which this envelope has been added is supplied to the D/A converter 12.

The D/A converter 12 converts the digital musical tone signal output from the multiplier 11 into an analog musical tone signal. The output of this D/A converter 12 is supplied to a sound system 13.

The sound system 13 includes an amplifier 13a and a speaker or headphones 13b, and converts an analog musical tone signal as an electric signal supplied from a D/A converter into an acoustic signal and emits sound.

FIG. 3 is a diagram for explaining the storage format of one musical tone waveform data stored in the waveform memory 9. As shown in FIG.

That is, one tone waveform data is made up of, for example, 16 words, and is stored sequentially from the rising portion of the tone to the repeating portion with the start address SA at the beginning. The loop address LT is the starting address for repeated reading, and the loop end address LE is the ending address for repeated reading. When generating one continuous musical tone corresponding to the pressed state of a key on the keyboard 4, reading out the musical waveform data starts from the start address SA, and when the loop end address LE is reached, the loop top address L is generated.
Return to A and continue reading, and the following loop top address L
By repeatedly reading the question between A and the loop end address LE, a sustained musical tone is generated.

FIG. 4 is a diagram for explaining a method of storing musical waveform data in the waveform memory 9, which is a feature of the present invention. The tone waveform data is stored in the format shown in FIG.

First, the original musical sound waveform as shown in FIG. 2(a) is imported as PCM data. Then, a section A of the rising portion of the original musical sound waveform and a section B of the sustained tone portion following it are arbitrarily determined. Next, define an arbitrary section C after section B,
FFT the frequency characteristics (overtone level data) of that section C.
(fast Fourier transform) etc. Waveforms are synthesized based on the data obtained in this manner and are connected to obtain a synthesized wave as shown in FIG. 4(b).

Next, the waveform data in section B is weighted with attenuation characteristics, that is, fade-out characteristics, and the rise characteristics, that is, fade-in characteristics are weighted in the same section as section B of the composite wave shown in FIG. In this case, the fundamental pitch of the original sound waveform and the fundamental pitch of the synthesized wave should be equal. The two weighted waveform data are added, and a so-called cross-fade mix is performed as shown in FIG. 4<c>.

The waveform memory 9 contains the rising part A of the original music waveform,
A waveform (section D) that is a cross-fade mix of section B of the original musical sound waveform and the synthesized wave, and one cycle of the synthesized wave that has not been weighted (section E) are stored continuously, and this is
Two tone waveform data. The beginning of section A is assumed to be a start address SA, the beginning of section E is assumed to be a loop top address LT, and the end thereof is assumed to be a loop end address LE.

The start address SA, loop top address LT, and loop end address LE determined in this way are stored in the ROM 2 in association with the musical tone waveform data.

If the musical sound waveform data stored in this way is read out sequentially from the start address SA, the rising part of the original musical sound waveform will be sounded first, then it will smoothly transition to the composite wave by the cross-fade part, and finally it will not be weighted. By repeatedly reading out one wavelength of the synthesized wave, it is possible to obtain a natural sustained sound without discontinuities.

FIG. 2 shows an embodiment of the tone generator 8. In FIG. 1, the frequency number, start address SA, loop top address LT, and loop end address LE are all information sent from the CPUI.

The latch 21 temporarily stores a frequency number corresponding to a key code output from the keyboard 4. Similarly, latches 22 and 23 temporarily store the loop top address LT and loop end address LE.

The selector 24 selects and outputs either the start address SA or the output of the latch 25, which will be described later.
At the start of sound generation, a control section (not shown) selects the H side and outputs the start address SA.

The adder 26 adds the frequency number stored in the latch 21 and the output of the selector 24, thereby generating a read address for the waveform memory 9.

The adder 27 subtracts the loop end address LE stored in the latch 22 from the addition result of the adder 26, so that the read address becomes the loop end address LE.
It is designed to judge whether or not the limit has been exceeded.

The selector 28 selects the carry-out signal Co of the adder 27.
Depending on ut, either the loop end address LE stored in the latch 22 or the loop top address LT stored in the latch 23 is output and supplied to the adder 29.

The two adders add the output of the adder 27 and the output of the selector 28, and the addition result is supplied to the latch 25.

The latch 25 temporarily stores the output of the adder 29, and the output of this latch is supplied to the waveform memory 9 and used as an address from which musical waveform data is read. Further, the output of the latch 25 is supplied to the L side of the selector 24, and is used to calculate the next read address.

Next, the operation of the tone generator having the above configuration will be explained.

First, the frequency number is set in the latch 21, the loop end address LE is set in the latch 22, and the loop top address LT is set in the latch 23 from the CPUI. In addition, the selector 24 is controlled by a control section (not shown).
l is selected.

In this state, when the start address SA is supplied to the selector 24, in the first time slot, the adder 26
The frequency number and start address SA are added to calculate the read address of the waveform memory 9.1 Next, the loop end address LE stored in the latch 22 is subtracted by the adder 27 from the read address output by the adder 26. . At this time, unless the read address exceeds the loop end address LE, the carry-out signal Cout does not become active, and the selector 28 selects Lll and supplies the loop end address LE to the adder 29. Thereby, the adder 29 adds the output of the adder 27 and the loop end address LE.

This means that the amount subtracted by the adder 27 is added again, and the adder 29 outputs the same output as the adder 26. , this is set in the latch 25 and becomes the read address of the waveform memory 9.

In the next time slot, the selector 24 is controlled so that the L side is selected. Therefore, by performing the same operation as described above, the frequency number is added to the current read address to calculate the next read address, which is then supplied to the waveform memory 9.

In this way, read addresses are calculated sequentially, and when the read address exceeds the loop end address LE, the adder 27 outputs an active carry-out signal C.
When out is output, the selector 28 selects the H side. As a result, one input of the adder 29 is supplied with the loop top address LT. On the other hand, the output of the adder 27 is supplied to the other input of the adder 29, and by adding these, the read address is corrected for the amount that protrudes from the loop top address LT or the loop end address LE. value is obtained.

By repeating the above operations, the musical tone corresponding to the key code will continue to be produced.

FIG. 5 shows a waveform diagram when the tone generator 8 is used to generate a continuous musical sound wave whose repetitive part (the part surrounded by the loop top address LT and the loop end address LE) is a sine wave of one period. As shown in Figure 6, a smooth sine wave musical tone signal with no discontinuities can be obtained.

FIG. 6 shows the frequency characteristics of the musical tone waveform shown in FIG. It is possible to obtain high-quality musical tones without generating unnecessary high-order overtones.

Next, the operation of the electronic musical instrument shown in FIG. 1 will be explained with reference to the flowchart shown in FIG.

First, when the operation is started by turning on the power, etc., tone initialization processing is performed (step Sl). In other words, a tone pointer that specifies the tone to be emitted is set to an initial value, and the tone color pointer specified by this tone pointer is set to an initial value. The initial tone color data stored in the tone color table in the ROM 2 is sent to the tone generator 8.

Next, by inputting switch data from the panel 7 via the input/output interface 6, it is possible to check whether or not a switch has been operated on the panel 7 (step S2).
), when it is determined that a switch on the panel 7 has been operated, a tone pointer in the tone table is set in accordance with the operation (step S3).
The tone data specified by the tone pointer is output to the tone generator 8, and the tone generator 8 gives it to the waveform memory 9 as an upper address (not shown), so that the musical waveform data of the corresponding tone in the waveform memory 9 is stored. selected.

On the other hand, if it is determined in step S2 that no switch has been operated on the panel 7, it is determined whether or not a key has been pressed by reading the data of the keyboard 4 via the input/output interface 6 (step S4). , and when it is determined that a key has been pressed, a sound generation process is performed (step S5). This sound generation process involves transmitting data corresponding to the tone, touch, and range to the tone generator 8 and envelope generator IO. This process instructs the start of pronunciation. This causes the sound system 13 to produce musical tones.

On the other hand, if it is determined in step S4 that no key has been pressed, the keyboard 4 is
By reading the data, it is determined whether or not the key has been released (step S6).

When it is determined that a key has been released, a mute process is performed (step S7). This mute process transfers data corresponding to the tone, touch, and range to the tone generator 8 and envelope generator 10 to generate sound. This is a process that instructs termination. As a result, sound generation from the sound system 13 is stopped. At this time, the sound generation is not completely stopped, but some sound accompanying the release of the key remains.

When the above series of processes is completed, the process returns to step S2 and the above-described operations are repeatedly executed. This causes panel 7
The sound is emitted or stopped while changing the tone color in accordance with the switch operation or the key press or release of the keyboard 4.

[Effects of the Invention] As described in detail above, according to the present invention, even when waveform data of a predetermined period in a specific section at the end of the waveform memory is repeatedly read out, discontinuous parts do not occur in the repeated parts, so that the musical tone is It is possible to provide a musical tone generating device that allows for a natural connection between the two and prevents the generation of unnecessary high-order overtones, thereby producing high-quality musical tones.

[Brief explanation of the drawing]

1rM to 7 show embodiments of the present invention, and FIG. 1 is a block diagram showing the schematic configuration of the electronic musical instrument, and FIG.
The figure is a block diagram showing the configuration of the tone generator.
The figure shows the storage format of the waveform memory, FIG. 4 is a diagram for explaining the musical sound waveform data stored in the waveform memory, and FIG. 5 shows an example of the musical sound waveform obtained by applying the present invention. 6 is a diagram showing the frequency characteristics of the musical sound waveform shown in FIG. 5, FIG. 7 is a flowchart for explaining the operation, and FIGS. 8 and 9 are for explaining the conventional musical tone generating device. 8 is a diagram showing an example of a musical tone waveform obtained by the conventional method, and FIG. 9 is a diagram showing the frequency characteristics of the musical tone waveform shown in FIG. 8. 1...CPU, 2...ROM, 3...RAM, 4
... Keyboard, 5... Touch sensor, 6... Input/output interface, 7... Panel, 8... Tone generator, 9... Waveform memory, 10... Envelope generator, 11... - Multiplier, 13...Sound system. Applicant: Kawai Musical Instruments Manufacturing Co., Ltd.

Claims (1)

[Scope of Claims] A waveform memory is provided in which waveform data of a rising portion of a musical tone and waveform data of a steady portion of a musical tone following the rising portion of the musical tone are stored in advance, and the waveform data of the rising portion of the musical tone is stored in one. The musical tone generating device generates a musical tone by repeatedly reading out the waveform data of a steady portion of the musical tone after reading it twice, and the waveform data stored in the waveform memory includes the waveform data of the rising portion of the musical tone and the following musical tone. The predetermined section contains single-period synthesized waveform data synthesized based on waveform data included in a predetermined section of the steady portion of the musical tone weighted with a damping characteristic and waveform data of an arbitrary section of the steady portion of the musical tone. waveform data with the same number of waves connected and weighted according to the rise characteristics,
This is followed by the single-period synthesized waveform data.